Slogan of ultrasonic diagnosis

Any discussion of toxicity without dose is hooliganism. First of all, our bodies are basically healthy, and it is impossible to go to the hospital for CT every day. Secondly, as a means of diagnosis and treatment, CT manufacturers will consider the possible harm to human body when designing. Therefore, in actual use, manufacturers will set up a lot of safety measures to prevent radiation damage to the human body. Finally, there is radiation in CT, but the dose of this radiation is not high and will not affect people's health.

First, let's talk about what radiation is. Radiation is a high-energy particle beam. General radiation is divided into ionizing radiation and electromagnetic radiation. Another name for electromagnetic radiation is electromagnetic wave. We use mobile phones to communicate, watch TV, use computers and use WIFI to generate electromagnetic radiation. Electromagnetic radiation is harmless to human body. Recently, many news reports said that some old people and women maliciously damaged the base station, fearing that it would radiate. The radiation produced by the base station is actually electromagnetic radiation, which is completely different from ionizing radiation. After all, the base station is just a signal tower, not a nuclear reactor.

The principle of CT is to penetrate the human body with X-rays, and then form an image of the inside of the human body. So CT will produce ionizing radiation. We can all see the placard "Beware of ionizing radiation" at the entrance of the hospital CT room. Every time the human body receives CT examination, the maximum radiation dose received is 1-2 millisieverts. This radiation dose is quite small and can be ignored. When the CT machine is turned off, radiation does not exist. Therefore, CT scanning does not do much harm to the body. On the contrary, doctors can judge your cause as soon as possible through the results of CT. Give you better treatment.

Our fear of radiation comes from three events. First, the United States used atomic bombs to bomb Japan. Second, the Chernobyl nuclear accident in the Soviet Union. Third, the Fukushima nuclear accident in Japan. These three nuclear accidents have created a considerable nuclear radiation air force. But all fears come from the unknown, and it is precisely because we don't understand nuclear radiation that we feel that nuclear radiation is terrible.

First of all, radiation is everywhere in our daily life. Let's start with our sun. Nuclear fusion continues to occur on the surface of the sun. Everyone can understand the hydrogen bomb that keeps exploding on the surface of the sun. Because the temperature and pressure on the surface of the sun are sufficient, the nuclear fusion reaction of hydrogen bombs can continue all the time. We all know that sunlight has a spectrum, one end of which is red light and the other end is purple light. The wavelength of violet light is short, and that of red light is long. All of the above are visible light, besides red light, there are infrared light, and besides violet light, there are ultraviolet light. Both are invisible light. Besides infrared rays, there are also radio waves and microwaves. These are all electromagnetic radiation that is harmless to human body.

If the wavelength of electromagnetic radiation is less than 100 nm, ionizing radiation will be formed. For example, X-rays and gamma rays are all ionizing radiation. Long-term high-dose ionizing radiation will cause cancer in human cells. But the premise is that the dose is large and the time is long. Short-term irradiation of CT will not cause problems.